Cybernetics and the steersman

Feedback can be very useful - particularly for control. Consider the case of the steersman (which gives the name Cybernetics) responsible for ensuring a boat follows a given course despite the effects of winds and tides.

Without feedback, the steersman would perhaps point the boat towards the correct destination and in effect keep his eyes closed and hope that the boat ends up at the right place. However winds or tides would push the boat off course and the steersman would not know - as he can't see. Inevitably the boat will not go where it should.

The solution - feedback - the course the boat is following is found and that information is fedback to the steersman (achieved by the steersman looking to see where he is going!). If the boat is off course the steersman takes the appropriate action, turning the rudder left or right, to get back on course.

Effectively you see what your system (in this case the boat) is doing, and if it is not doing the right thing (here the boat is off course), suitable corrective action is taken (the rudder is turned left or right).

It's a nice concept, easily extended to other systems.
 

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